#include <bits/stdc++.h>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, x, y, used[100001], cnt;
vector<vector<int>> adj(100001);

void dfs(int nod){
    used[nod] = 1;
    for(int a : adj[nod])
        if(used[a] == 0)
            dfs(a);
}

int main(){

    fin >> n >> m;
    for(int i = 1; i <= m; i++){
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    for(int i = 1; i <= n; i++){
        if(used[i] == 0)
            dfs(i), cnt++;
    }

    fout << cnt;
}